Evaporation

This report describes laboratory work carried out to evaluate and further optimise the chemical and physical formulation of the proposed new ultra-thin film product. Three chemical systems were evaluated—EX1, EX2 and EX3.

Evaporation water losses from irrigation channels are an important component of total irrigation system losses and could be as much as 12% in the Goulburn Murray channel network. The effectiveness of monolayers has been widely studied in still water storages. This research project investigated the potential of using chemical monolayers on irrigation channels in order to suppress evaporation.

Evaporation accounts for the biggest water losses in the nation, which means the potential shown from recent evaporation research and development, involving on-farm and major storage trials, should continue to be explored.

The National Centre for Engineering in Agriculture (NCEA) recently undertook seepage and evaporation measurements at water storages for a mixed horticulture farm at Forest Hill in the Lockyer Valley. This is a fact sheet about those measurements.

A large proportion of irrigation research is understandably aimed at efficient use of water extracted from storages for food production but attention is also given to reducing losses that occur through evaporation.

We have gathered together all our evaporation research projects, reports, facts sheets and links to other relevant information below.

Evaporation is a significant loss component from irrigation dams, and although numerous evaporation reduction methodologies exist, their adoption is hindered since they are deemed uneconomical. Any cost/benefit analyses that are done are generally based on poor evaporation estimates due to the complexities involved in evaporation prediction.
One area of uncertainty is the significance of night time evaporation. Similarly, the role of windsheltering on evaporation can be significant but is (more)…

Publications & Videos

This report describes laboratory work carried out to evaluate and further optimise the chemical and physical formulation of the proposed new ultra-thin film product. Three chemical systems were evaluated—EX1, EX2 and EX3.

The National Centre for Engineering in Agriculture (NCEA) recently undertook seepage and evaporation measurements at water storages for a mixed horticulture farm at Forest Hill in the Lockyer Valley. This is a fact sheet about those measurements.

This report documents the numerical analysis performed for the Land and Water Australia (LWA) National Program for Sustainable Irrigation project "The significance of night time evaporation from irrigation farm dams” under contract UWA45.
The objective of the present study is to further develop the numerical model DYRESM to make it applicable to irrigation farm dams and to subsequently apply it to gain (more)…

Right now, it is very difficult to accurately measure the water losses from evaporation on farm dams but a recent scoping study funded by the National Program for Sustainable Irrigation estimated the loss is as high as 7,000 gigalitres per year from Queensland’s section of the Murray-Darling Basin alone.
Given that water extracted from our waterways for all purposes is around 20,000 gigalitres per annum in the whole of Australia, the potential savings from addressing evaporation losses (more)…

As much as 40% of water stored in a farm dam can be lost through evaporation, depending on the depth of the dam and its surface area. Dam design can significantly decrease evaporation by reducing the surface area to volume ratio (deeper, narrower dams) and planting windbreaks to provide shade and reduce wind turbulence.
Over the years, a number of commercial products have also been developed to minimise water losses, including floating plastic covers and chemical products that change the (more)…

Evaporation reduction from farm dams in Australia is regarded as one of the few areas where there are real water savings to be made. At this stage, there are a number of commercial evaporation reduction systems available that use either a hard or polymer cover.
Currently these systems are deemed to be viable (M. Durack pers. comm., 2004) for high value crops such as table grapes but are generally not financially viable for lower value crops such as sorghum or cotton. The Department of (more)…

News

National Program for Sustainable Irrigation partner Goulburn-Murray Water is making a major contribution to the evaluation of thin films, or monolayers, which can spread over water surfaces to reduce evaporation.

The National Program for Sustainable Irrigation has had an active interest in evaporation as a researchable issue for more than 10 years, looking at the big picture as well as farm-based practices to reduce evaporative loss. It was a sponsor of an international workshop at the Gold Coast in 2009, for example, to address priorities and foster the exchange of knowledge.

Evaporation accounts for the biggest water losses in the nation, which means the potential shown from recent evaporation research and development, involving on-farm and major storage trials, should continue to be explored.

Farm dam management has been a particular interest of the National Program for Sustainable Irrigation, with much of the work undertaken by Deb Atkins of Industry Investment NSW in a collaborative project as part of the former CRC for Irrigation Futures.